Distillate fuel oil containing nitrogen-containing salts or amides as was crystal modifiers

ABSTRACT

Addition to distillate fuel oil of wax crystal modifying amides or salts, of limited oil solubility, formed from acids with amines or ammonia improves the cold-flow properties of the oil.

United States Patent Hollyday, Jr.

[ 1 Apr. 25, 1972 [54] DlSTILLAT-E FUEL OIL CONTAINING NITROGEN-CONTAINING SALTS OR AMIDES AS WAS CRYSTAL MODIFIERS [72] inventor: Wllllam C. l-lollyday, .Ir., Watchung, NJ.

[73] Assignee: Esso Research and Enflneerlng Company,

7 Linden, NJ.

[22] Filed: Sept. 15, 1969 [21] Appl. No.: 858,180

[52] US. Cl ..44/62, 44/66, 44/71, 44/72, 44/75 [51] Int. Cl ..C10l1/l8, C101 1/22 [58] Field of Search ..44/58, 62, 66, 71, 72, 75

[56] References Cited 1 UNITED STATES PATENTS 2,296,069 9/1942 Talbert et a1.... ..44/72 X 2,433,243 12/1947 Smith et al.... ..44/66 2,604,451 7/1952 Rocchini ....44/71 X 2,798,045 7/1957 Buck et a1 ..44/66 X 2,861,874 11/1958 OKelly et a]. ..44/72 X 2,888,340 5/1959 Winnick ..44/62 X 2,939,842 6/1960 Thompson ..44/71 X 2,951,751 9/1960 McDermott ..44/66 X 3,029,136 4/1962 Myers ..44/66 3,048,479 8/ 1962 llynckyj et a1. ..44/62 3,166,387 1/1965 Ebner ..44/62 3,275,427 9/ 1966 Brownawell et a1. ..44/62 3,337,313 8/1967 Otto ..44/62 FOREIGN PATENTS OR APPLICATIONS 993,744 6/1965 Great Britain ..44/62 676,875 12/1963 Canada ..44/62 Primary Examiner-Daniel E. Wyman Assistant Examiner-W. J. Shine Attorney-Pearlman and Stahl and Frank T. Johmann [57] ABSTRACT Addition to distillate fuel oil of wax crystal modifying amides or salts, of limited oil solubility, formed from acids with amines or ammonia improves the cold-flow properties of the oil.

17 Claims, No Drawings DISTILLATE FUEL OIL CONTAINING NITROGEN- CONTAINING SALTS R AMIDES AS WAS CRYSTAL MODIFIERS BACKGROUND or THE INVENTION 1. Field of the Invention Distillate fuel oils, which form wax crystals at low temperatures during use, are modified by the addition of certain nitrogen materials of limited solubility in the fuel oil, having at least one straight chain hydrocarbon segment of at least six carbon atoms, e.g. amides and ammonium or amine salts, which nitrogen materials modify the shape of the wax crystals that form to thereby decrease blocking and stoppage of fuel and delivery lines. These nitrogen materials may also be utilized to advantage with ethylene polymeric pour point depressants, particularly those polymers 'wherein a polyethylene backbone resulting from ethylene polymerization is divided by side groups or branches, into segments. These side groups include hydrocarbons, esters, ketones, chlorine, or other groups, and usually result from copolymerizing the ethylene with a comonomer, e.g. vinyl acetate, or they can result from homopolymerization of the ethylene, or by chlorinating polyethylene, etc.

2. Description of the Prior Art Kerosene, which acts as a solvent for n-paraffin wax, had traditionally been a component of middle distillate fuel oils. Recently, with the increased demands for kerosene for use in jet fuels, the amount of kerosene used in middle distillate fuel oils has decreased. This, in turn, has frequently required the addition of wax crystal modifiers, e.g. pour point depressant additives, to the fuel oil to make up for the lack of kerosene. The more effective of these distillate oil pour depressants are copolymers of ethylene with various other monomers, e.g. copolymers of ethylene and vinyl esters of lower fatty acids such as vinyl acetate (U.S. Pat. No. 3,048,479); copolymers of ethylene and alkyl aerylate Canadian Patent 676,875); terpolymers of ethylene with vinyl esters and alkyl fumarates (U.S. Pat. Nos. 3,304,261 and 3,341,309); polymers of ethylene with other lower olefms, or homopolymers of ethylene (British Patents 848,777 and 993,744); chlorinated with certainty why the amides and salts of the invention are effective, but it is believed that they may act as nucleating agents for the wax. Thus, due to their low solubility in the fuel oil, these materials are believed to precipitate from the cooling oil to form small crystals which in turn serve as nuclei for the wax to crystallize onto. By having a large number of nucleation sites present when the wax begins to crystallize, a correspondingly large number of crystals form. Since the supply of wax is limited, the individual crystals do not generally grow very large and the resulting small crystals will pass through the screens and filters during commercial distribution of theheating oil.

SUMMARY OF THE INVENTION The amides and salts of the invention will usually total 7 to 60, preferably 12 to 30 carbons and have at least one straight chain hydrocarbon segment of at least six carbon atoms. It is polyethylene (Belgium Patent 707,371 and US. Pat. No. I

3,337,313); etc. However, in general, these ethylene backbone pour point depressants, while very effective in lowering the pour point of distillate oil,.sometimes result in wax crystals having large particle sizes ranging from I millimeter upto an inch in their larger dimensions. These large particles tend to be filtered out by the screens and other filter equipment normally used on delivery trucks and fuel oil storage systems, with a resulting plugging of these screens and filters even though the temperature of the oil is substantially above its pour point. The present invention is based on the discovery that certain classes of amides, and ammonium and amine salts, result in small particle size crystals which are usually sufficiently small to pass through the screens and filter equipment so as not to cause plugging, and at the same time do not unduly interfere with the action of the pour point depressant in preventing the oil from freezing.

In my prior patent, US. Pat. No. 2,852,467, it was found that fatty acid salts of alkylene imine polymers were effective as pour point depressants in lubricating oil. Also, in US. Pat. No. 3,166,387, it was found that certain fatty acid salts of a secondary or tertiary monoamine having at least two C alkyl groups, were effective as pour point depressants in distillate fuel oils. In contrast to the two aforesaid patents, the amides and salts of the present invention are not pour depressants for distillate fuel, they can have little or no branching, they have a low solubilityin the oil at room temperature, i.e. 77 F., as opposed to pour point depressants-which by their very nature tend to have higher solubility in oil at room temperature in the absence of wax. While not pour point depressing agents for distillate fuel, these amides and salts of the invention are effective agents for controlling the size of the wax crystals that form during cooling of the oil. It is not known believed this segment provides sites on the amide or salt crystal for the n-paraffin wax molecules to adhere onto, thereby encouraging the wax molecules to start their crystallization onto the already formed amide or salt crystals. These amides and salts are formed from (1') an acid component including monoor dicarboxylic acid, phenol, inorganic acid, sulfonic acid, etc., reacted with (2) a nitrogen component including ammonia, monamines, polyamines, hydroxy amines, etc. Usually equal molar equivalents of the acid and nitrogen components, i.e. one acid group per one nitrogen group, will be reacted together, although in many cases a slight excess (e.g. up to about 1 molar equivalent excess) of acid may be used to drive the salt or amide formation to completion. On the other hand, it will be apparent that with polyacids or polyamines,. less than equal molar equivalents may be used. For example, one mole of monocarboxylic acid can be reacted with one mole of tetraethylenepentamine, and this is also within the scope of the present invention although it is less preferred since the test data indicates maximum effectiveness occurs with the aforesaid one to one molar equivalent ratio.

As will later be seen, some of these nitrogen materials are more effective than others. In general, it appears that the more linear the salt or amide, the more effective it is. This is believed due to the fact that the more linear materials will pack more closely together and more readily crystallize to form nuclei for the subsequent wax crystallization. Thus, salts or amides from straight chain, or slightly branched, acid and/or nitrogen components are preferred as they generally perform better than highly branched materials. Also, mixed acids or mixed amines appear to be less effective than unmixed acids or unmixed amines in forming the salt or amide. This, too, is believed related to crystal formation.

The mono and dicarboxylic acids utilized in the invention can be represented by the general formula: R(COOI-I),, where n is l or 2, and R is a hydrocarbon group of one to 29, e.g. three to 18, carbon atoms. R can be unsubstituted or substituted (e.g. hydroxy substitiited), saturated, unsaturated, or aromatic, and includes aliphatic, aryl, alicyclic, alkaryl, and hydroxy alkyl groups, etc. Examples of such acids include formic, acetic, hexanoic, lauric, myristic, palmitic, margaric, stearic, hydroxy stearic, behenic, naphthenic, salicyclic, acrylic, fumaric, maleic, etc. Mixtures of acids such as the commercial tallow acids, coconut acids, etc., may also be used. Preferred are the straight chain monocarboxylic acids, i.e. fatty acids.

Phenols which may be used include phenol, and alkylated phenol wherein the phenol is substituted with one to three alkyl groups of one to 12 carbons, etc.

Examples of inorganic acids include the mineral acids such as sulfuric acid, hydrochloric acid, sulfurous acid, the various The monoamines of the invention can be primary, secondary or tertiary and are represented by the fonnula:

wherein R, is a C, to C hydrocarbon group while R and R are each hydrogen or a C to C preferably a C, to C,,, hydrocarbon group. The chain length of R and R is kept short to keep oil-solubility limited so the final product functions as a nucleation agent. Longer side chains, i.e. R and R values of C and higher would tend to increase oil solubility to an undesirable extent. The hydrocarbon groups are preferably aliphatic, e.g. alkyl groups, and can be unsubstituted or substituted, e.g. hydroxy substituted.

Examples of primary amines include tridecyl amine, n-octyl amine, C Oxo amine, n-dodecyl amine, coco amine, tallow amine, behenyl amine, etc. Examples of secondary amines include diethyl amine, di-n-octyl amine, methyl-lauryl amine, dodecyl-octyl amine, coco-methyl amine, tallow-methyl amine, methyl-n-octyl amine, methyl-n-dodecyl amine, methyl-behenyl amine, etc. Examples of tertiary amines include triethylene amine, coco-diethyl amine, cyclohexyldiethyl amine, coco-dimethyl amine, tri-n-octyl amine, dimethyl-dodecyl amine, methyl-ethyl-coco amine, etc. Examples of hydroxy substituted amines include monoethanol amine, diethanol amine, triethanol amine, diisopropanol amine, etc.

As previously mentioned, polyamines can also be used. The most common commercial ones are the ethylene amines having two to ten nitrogens such as ethylenediamine, diethylenetriamine, tetra-ethylenepentamine, etc.

Amine mixtures may also be used and many amines derived from natural materials are mixtures. Thus, coco amine derived from coconut oil is a mixture of primary amines with straight chain alkyl groups ranging from C to C Another example is tallow amine, derived from hydrogenated tallow, which is a primary amine with a mixture of C, to C,, straight chain alkyl groups.

The amides can be formed in a conventional manner by heating the amine and acid with the removal of the water of reaction. The salts are also conventionally prepared by simply mixing the amine and the acid together with stirring at room temperature, e.g. 77 F., or by blowing ammonia through the acid.

The nitrogen materials, or nucleation agents, of the invention can be utilized with pour depressants, and in many cases will reduce the amount of pour depressant that is required to give the fuel oil the desired degree of fluidity at low temperatures. in general, these polymeric pour depressants have a polymethylene backbone which is divided into segments by hydrocarbon or oxyhydrocarbon side chains. Generally, they will comprise about three to 40, preferably four to 20, molar proportions of ethylene per molar proportion of a second ethylenically unsaturated monomer, which latter monomer can be a single monomer or a mixture of such monomers in any proportion. These oil-soluble polymers will generally have a number average molecular weight in the range of about 1,000 to 50,000, preferably about 1,000 to about 5,000, as measured for example, by Vapor Phase Osmometry, such as using a Mechrolab Vapor Phase Osmometer Model 310A.

The unsaturated monomers, copolymerizable with ethylene, include unsaturated mono and diesters of the general fonnula:

wherein R, is hydrogen or methyl; R, is a OOCR, or COOR, group wherein R, is hydrogen or a C, to C preferably a C, to C,, straight or branched chain alkyl group; and R is hydrogen or COOR,. The monomer, when R, and R are hydrogen and R, is OOCR, includes vinyl alcohol esters of C to C monocarboxylic acids, preferably C to C monocarboxylic acid. Examples of such esters include vinyl acetate, vinyl isobutyrate, vinyl laurate, vinyl myristate, vinyl palmitate, etc. When R is COOR,, such esters include methyl acrylate, isobutyl acrylate, methyl methacrylate, lauryl acrylate, palmityl alcohol ester of alpha-methyl-acrylic acid, C Oxo alcohol esters of methacrylic acid, etc. Examples of monomers where R, is hydrogen and R and R, are -COOR groups, include mono and diesters of unsaturated dicarboxylic acids such as: mono C Oxo fumarate, di-C Oxo fumarate, di-isopropyl maleate; di-lauryl fumarate; ethyl methyl fumarate; etc.

The Oxo alcohols mentioned above are isomeric mixtures of branched chain aliphatic primary alcohols prepared from olefins, such as polymers and copolymers of C to C, monoolefins, reacted with CO and hydrogen in the presence of a cobalt-containing catalyst such as cobalt carbonyl, at temperatures of about 300 to 400 F., under pressures of about 1,000 to 3,000 psi., to form aldehydes. The resulting aldehyde product is then hydrogenated to form the Oxo alcohol which is then recovered by distillation.

The aforementioned second monomers also include ketones containing a total of four to 24 carbons which can be represented by the general formula:

iii.

wherein R is a C, to C hydrocarbon group such as aryl, alkaryl, cycloalkane, straight or branched chain alkyl group, etc. R is hydrogen or a C, to C alkyl group. Preferably, R is a C, to C alkyl group and R is hydrogen. Examples of such ketones include vinyl methyl ketone (i.e., R is hydrogen and R is methyl), vinyl isobutyl ketone, vinyl n-octyl ketone, vinylisooctyl ketone, vinyl dodecyl ketone, vinyl-phenyl ketone, vinyl-naphthyl ketone, vinyl-cyclo-hexyl ketone, 3-pentein-2- one, i.e. R is methyl and R is methyl, etc.

Another class of monomers that can be copolymerized with ethylene include C, to C alpha monoolefins, which can be either branched or unbranched, such as propylene, isobutene, n-octene-l isooctene-l, n-decene-l, dodecene-l, etc.

Still other monomers include vinyl chloride, although essentially the same result can be obtained by chlorinating polyethylene. Or as previously mentioned, branched polyethylene can be used per se as the pour depressant.

These copolymer pour depressants are generally formed using a free radical promoter, or in some cases they can be formed by thermal polymerization, or they can be formed by Ziegler catalysis in the case of ethylene with other olefins. The polymers produced by free radicalappear to be the more important and can be formed as follows: Solvent, and 0-50 wt. of the total amount of monomer other than ethylene, e.g. an ester monomer, used in the batch, are charged to a stainless steel pressure vessel which is equipped with a stirrer. The temperature of the pressure vessel is then brought to the desired reaction temperature and pressured to the desired pressure with ethylene. Then promoter, usually dissolved in solvent so that it can be pumped, and additional amounts of the second monomer, e.g. unsaturated ester, are added to the vessel continuously, or at least periodically, during the reaction time, which continuous addition gives a more homogeneous copolymer product as compared to adding all the unsaturated ester at the beginning of the reaction. Also during this reaction time, as ethylene is consumed in the polymerization reaction, additional ethylene is supplied through a pressure controlling regulator so as to maintain the desired reaztion pressure fairly constant at all times. Following the completion of the reaction, the liquid phase of the pressure vessel is distilled to remove the solvent and other volatile constituents of the reacted mixture, leaving the polymer as residue. Usually, to facilitate handling and later oil blending, the polymer is dissolved in a light mineral oil to form a concentrate usually containing 25 to 60 wt. polymer.

Usually, based upon 100 parts by weight of copolymer to be produced, then about 50 to 1,200, preferably 100 to 600, parts by weight of solvent, and about 5 to 20 parts by weight of promoter will be used.

The solvent can be any non-reactive organic solvent for furnishing a liquid phase reaction which will not poison the catalyst or otherwise interfere with the reaction, and preferably is a hydrocarbon solvent such as benzene, cyclohexane, and hexane.

In general, the promoter can be any of the conventional free radical promoters, such as peroxide or azotype promoters, including the acyl peroxides of C, to C branched or unbranched carboxylic acids, as well as other common promoters. Specific examples of such promoters include dibenzoyl peroxide, di-tertiary butyl peroxide, di-tertiary butyl perbenzoate, tertiary butyl hydroperoxide, di-acetyl peroxide, di-ethyl peroxycarbonate, cumene hydroperoxide, alpha, alpha, azo-diisobutyronitrile, di-lauroyl peroxide, etc.

The temperature used during the reaction will usually depend upon the choice of the free radical promoter and its rate of decomposition, and will usually range from 70 to 250 C.

The reaction pressures employed will usually be in the range of 800 to 10,000 psig., for example 900 to-6,000 psig. This pressure can be attained by maintaining a fairly continuous and constant pressure on the reaction chamber through controlling the inlet feed of ethylene.

The time of reaction will depend upon, and is interrelated to, the temperature of the reaction, the choice of promoter, and the pressure employed. In general, however, one-half to 10, usually I to 5, hours will complete the reaction.

The final composition of the invention will generally comprise a major amount of the distillate containing fuel oil and about 0.001 to 1 wt. preferably 0.005 to 0.15 wt. of the aforementioned described amide or salt nucleation agent. In addition, the composition can also contain about 0.001 to 2 wt. preferably 0.005 to 0.15 wt. of the aforedescribed methylene backbone pour point depressant. Said weight percents are based on the weight of the total composition.

The hydrocarbon oils, which are treated for pour depression with the nucleation agents of this invention, include cracked and/or virgin distillate heating oils boiling from about 300 up to about 750 F., e.g., No. l and 2 Fuel Oils. However, these distillate heating oils may also be blended with 0 to 70 wt. preferably 0 to 30 wt. based on the total weight of oil, of residua-fuel. However, while effective on the n-paraffins in distillate oils, and aside from the polyamine salts operable in lube oil, a number of other nucleating agents of the invention were tried in lube oil, 100 percent residua fuel, and also crude oil, and had no effect on improving flow.

The nucleation agents of the invention may be used alone as the sole oil additive, or in combination with other oil additives such as pour depressants or other flow improvers; corrosion inhibitors; antioxidants; sludge inhibitors; sludge dispersants; etc.

The invention will be further understood by reference to the following Examples which include preferred embodiments of the invention.

in these Examples the following materials were used:

Heating Oil This was a mixture of 20 volume percent straight run stock and 80 volume percent of crack stock. This heating oil had a cloud point of 24 F., a pour point of +20 F., an aniline point of 135 F an initial boiling point of 370 F and a final boiling point of 644 F.

Pour Depressant A This was a concentrate of 48 wt. light mineral oil and about 52 wt. ethylene-vinyl acetate copolymer having a number average molecular weight of about 2,605 by Vapor Phase Osmometry, having about l0-l2 methylene terminated branches per hundred carbon atoms in the backbone, and a relative molar ratio of about 6.8 moles of ethylene per mole of vinyl acetate in the copolymer. This copolymer was prepared by copolymerizing ethylene and vinyl acetate using ditertiary butyl peroxide at a temperature of about 150 C. under 950 psig ethylene pressure.

A typical laboratory preparation of this polymer is as follows:

A three liter stirred autoclave was charged with l 150 ml. of benzene as solvent. The autoclave was then purged with nitrogen and then with ethylene. An initial charge of 40 ml. vinyl acetate was added. The autoclave was then heated to a temperature of about 150 C. 2 C., while ethylene was pressured into the autoclave to a pressure of 950 psig. Then, while maintaining the temperature at about 150 C., a solution consisting of 23 wt. di-tertiary butyl peroxide dissolved in 77 wt. benzene in order to facilitate pumping was continuously injected into the autoclave at a rate of 30 cc. per hour for 150 minutes. When peroxide addition was begun, additional vinyl acetate was continuously injected into the autoclave at the rate of ml. per hour for minutes. Additional ethylene was pressured periodically into the autoclave so as to maintain the pressure continuously at 950 psig. After all the peroxide and vinyl acetate was added, the contents of the autoclave were maintained at C. for an additional period of 15 minutes. Then the temperature of the reactor contents was quickly lowered to about 50 C. over about 20 minutes. The reactor was depressurized and the contents of the autoclave was discharged. The benzene was evaporated from the discharged contents over a steam bath, while blowing with nitrogen. The copolymer is then dissolved in a light mineral oil to form the concentrate.

Pour Depressant B This was a concentrate of 48 wt. terpolymer in mineral oil, the terpolymer having a number average molecular weight (VPO) of about 2,900, and comprising about 68.0 wt. ethylene, 25.5 wt. vinyl acetate, and 6.5 wt. of-di-C -Oxo fumarate. A typical preparation of this terpolymer is carried out in the same manner as the typi cal laboratory preparation of Pour Depressant A described above, except that the initial charge to the reactor consists of a mixture of about 80 wt. vinyl acetate and about 20 wt. of the di-C -Oxo fumarate.

Pour Depressant C This pour depressant was a random copolymer of ethylene and propylene, having a molecular weight of about 1,495, and a relative mole ratio of 12.3 molar proportions of ethylene per molar proportion of propylene. This was used in a concentrate of about 52 wt. copolymer in mineral oil.

Pour Depressant D This was a concentrate of 51 wt. oil and 49 wt. of a random copolymer of ethylene and isobutyl acrylate having a molecular weight of about 3,370, and a relative mole ratio of about 7.2 moles ethylene per mole of isobutyl acrylate, which copolymer was formed by free radical polymerization.

Flow test A This test was carried out in an hour-glass shaped cylindrical device having upper and lower chambers separated by a partition defining a capillary orifice. Forty ml. of oil are poured into the lower chamber, and the tester containing the oil is then chilled from a temperature of 10 F. above its ASTM cloud point, at a rate of 4 F. per hour, to a temperature 10 F. below the cloud point. The tester is inverted, allowing the now cloudy oil to flow by gravity into the empty lower chamber. The volume percent of the oil passing through the orifice in three minutes is noticed. if the wax is in large crystals, it of course, blocks the orifice and slows the oil flow. Small crystals, on the other hand, give good flow.

Flow Test B This test is carried out using the same test device and procedure as in A above, except the oil is cooled in a cold box from room temperature to 15 F., which had been 'determined as a critical temperature for the aforedescribed maintained at 15 R, where the small sample rapidly cools from room temperature (about 70-75 F.) to 15 F. in about two hours and is then tested. Due to the sudden cooling, this test is less severe than Flow Test A where the cooling is much slower.

EXAMPLE 1 l2 Hydroxy Stearamide An oil composition was prepared consisting of Heating Oil,

.02 wt. of a 12-hydroxy stearamide of the formula:

CH,(CH,),COHH(CH,) CONH and sufficient Pour Depressant A to give 0.044 wt. active ingredient (a.i.), i.e., 0.044 wt. of ethylene-vinyl acetate copolymer.

Similar compositions were made up using different proportions of Four Depressant A, as well as Pour Depressant B in place of A in the same Heating Oil. These compositions, as well as oil compositions containing the pour depressants without the amide, were tested in the aforesaid Flow Test A. The results are summarized in Table l which follows:

TABLE I.12-HYDROXY STEARAMIDE COLD FLOW IMP ROVE B Total wt. Wt. Flow percent a.l., Flow percent test A, polymer test A, a.i. percent plus .02% percent Pour depressant polymer passage amide passage Pour depressant A 0. 15 89 o 0. 04 58 0. 06 94 Pour depressant B 0. 03 50 0. 94

EXAMPLE ll Ammonium Salts Of Fatty Acids In this example, a series of ammonium salts were prepared by saturating a fatty acid solution in kerosene with ammonia until no more ammonia was absorbed. This reaction was carried out in the solvent at room temperature and a typical preparation is as follows:

1 1.6 gm. of hexanoic acid was added to 119.7 g. of kerosene in a 200 ml. round bottom flask connected to a source of ammonia gas slightly above atmospheric pressure. Absorption of the ammonia was allowed to continue for about 5 hours at 75 F. The reaction was completed when no more ammonia was absorbed as indicated by no further gain in weight of the contents of the flask. The salt separated, but could be resuspended by gentle shaking when a portion of the suspension was to be weighed out for making blends. Salts ranging from ammonium formate to ammonium triacontanoate were prepared by this method.

Various oil compositions were made up using Heating Oil and Pour Depressant A, with and without an ammonium salt. These compositions were tested according to Flow Tests A and B.

The exact compositions tested and the results obtained are summarized in the following Table 11:

TABLE II AMMONIUM SALTS OF FATTY ACIDS AS COLD FLOW IMPROVERS Wt. salt Wt. Flow test, of carboxylic a.i. pour passage acid Depressant A A B None 0.02 47 None 0.04 58 52 0.05% Hexanoate 0.04 93 100 0.08% Hexanoate 0.04 100 0.8% Heptanoate 0.04 Y 86 0.05% Octanoate 0.04 94 100 0.05% Decanoate 0.04 0.05% Neo-Decanoate 0.04 60 100 0.05% Undecanoate 0.04 100 0.03% Laurate 0.04 93 0.03% Coconate 0.04 96 100 0.03% Myristate 0.04 88 100 0.05% Myristate 0.04 90 0.01% Stearate 0.04 71 0.025% Stearate 0.02 93 0.025% Stearate 0.04 100 0.020 Stearate 0.04 93 0.03% Stearate 0.04 94 0.05% Stearate 0.04 81 0.015% Triacontanoate 0.04 100 0.020% Triacontanoate 0.04 100 0.025% Myristate 0.04 100 0.025% Stearate 0.04 100 0.05% Stearate 0.04 100 The Neo-Decanoate of Table II was prepared from neodecanoic acid which, on a weight basis, consists of 60 percent alpha, alpha di-methyl heptanoic acid, 30 percent alphamethyl, alpha-ethyl hexanoic acid, 5 percent of alpha, alpha di-alkyl carboxylic acid wherein the alkyl groups are other than methyl or ethyl, and 5 wt. isodecanoic acid wherein the branching is not at the alpha position.

The Coconate of Table 11 was obtained from coconut acid which on a weightpercent basis is a mixture of 4% C 4% C 45% C 15% C 14% C and 18% C,, saturated straight chain carboxylic acids.

As seen by Table 11, the ammonium salts drastically increased the flowability of the oil. In Flow Test B, wherein the oil is rapidly cooled to 15 F., 93 percent or more of the oil passed through the orifice within 3 minutes. Even in the more stringent Flow Test A, where the oil is more slowly cooled, the lowest result for a straight chain acid was a 71 percent passage, but this was only using 0.01 wt. of the Stearate salt. The Neo-Decanoate at the 0.05 wt. concentration gave 60 percent passage in Flow Test B, as opposed to a 100% passage using Decanoate, thereby illustrating the preference for straight chain alkyl groups rather than branched.

EXAMPLE lll Triethanol Amine Stearate Salt TABLE IIL-TRIEIIIANOL AMINE STEARAIE AS COLD FLOW IMPROVER Wt. percent trlotlninolnmlno stonrnto Percent passage,

Wt. percent pnnr Wt. percent pour flow test A depressant C l depressant l) l 1 Oil concentrate of 62 wt. percent ethylene-propylene copolymer. 1 Oil concentrate of 4'.) wt. percent ctliylene-isobutyl acrylato copolymer.

.As seen by Table III, the addition of 0.04 wt. of the TABLE M NE ALT AS COLD FLOW triethanol amine stearate gave a 9.6 percent flow when using IMPROVERS 0.08 wt. of either of the two different pour depressant con- Amine salt Flow centrates. Without this stearate salt present, 0.15 wt. of MOL percent ff ggfit fg g fi these pour depressant concentrates gave a significantly less 5 Amine Acid a t depressantA passage flow rate, showing that the pour depressants per se are not too t 0.02 100 effective in improving flow properties caused by the crystal- 232?? gf 8.82 0.04 100 lized wax. On the other hand, pour point tests on the o 'j 256 8:8; triethanol amine stearate showed that it had essentially no n'TetradwyL- 259 00 p point effectiveness n-Hexadecyl. 287 0.05 0. 04 100 Tallow ..do 315 8'8? 8'8; fig EXAMPLE v n-Dodecyl.... Acetic. .245 8: 13g r Tallow .do s29 01 04 o. 02 100 Tridecyl Amine Naphthenate and Tallow Amine Stearate 0. 0b 0. 02 100 Trldecyl Lauri0 391 0.05 0.02 70 These amine salts were prepared by simple mixing of the Tallow Stearic 553 8-32 8-8; 3% amine and the acid at 77 F. r 0:03 0:02 100 I1 Octyl 1 413 0 06 0 02 1 The tridecyl amine that was used is a mixture of C to C 83 mono amines with branched tertiary alkyl groups and primary "'Dodecyl 470 0106 0: 02 1 0 amine groups, with an average molecular weight of 191. rmdecyl "do 475 gg The naphthenic acid that was used is a mixture of saturated 2O Coco .410 494 0:03 0.' 02 100 straight chain, branched and cyclic carboxylic acids, including Cyclohexyl d0 383 ggg 3' 8g igg some keto and hydroxy acids. The minor components are. 3 100 Tallow ..do 553 o 06 0 02 100 phenolic materials and sulfur-containing acids. The average 70 molecular weight was 225. 596 i 02 60 -do 377 0. 05 0. 100 The results obtained when using these salts in Heating Oil Tridecylfl Behenic 521 0 05 0 02 100 are summarized in the following Table IV: 0. 03 0. 02 100 g "3 g 0. 00 0.02 too TABLE IV.--'IRIDEOYL' AMINE NAPH'IHENATE AND a 3; @3555? $2 3; 3; 38

TALLOW AMINE STEARATE mom 3() Do Phenol 363 Wt.percent ASTM Flow Do Furnaric 664 a.l. pour pour test B, 2 100 I depressant point, percent Wt. percent amine salt F. passage EXAMPLE v] None 0 +20 0 D 0. 02 54 3 5 Secondary and Tertiary Amine Salts 7 5 gfdfigh' h' '.;fif,' f,gfig 818% I 3 8 In this example, salts of secondary andtertiary amines were 8-85 z emiine p zienateu ggg 18 8 prepared and tested in Heating Oil using Pour Depressant A 'i ff i' 100 and Flow Test B. The results are summarized in Table VI which follows:

TABLE VLSECONDARY ANO TERTIARY AMINE SALTS AS COLD FLOW IMPROVERS Wt. per- Flow Amine salt Wt. cent 0.1. test B, Mol. percent pour dcpercent Amino Acid wt. salt pressant A passage Coco di-methyl Acetic 294 0.03 0.02 88 Do- For-mic. 280 0.03 0.02 80 Tri-ethyl Steanc 385 8:82 8:8; igg l- -buty .do 414 8: 8g 8: 3; $8 Arachidyl/behenyl (ii-methyl .do 624 0. 05 0. 02 100 Cyclohexyl di-ethyl .do 440 0g .0 Coco di-methyl d0 518 8. 8g 3.8g 18g Trl-ethyl Naphthenic. 326 01 05 0102 8:; Coco (Ii-methyl". Fumaric 584 0.03 0.02 90 As seen by Table IV, the salts made from the tridecyl amine EXAMPLE Vll naphthenate in which the alkyl groups present in both the tridecyl amine and the naphthenic acid portion of the salt y y Amine Saks were branched, was not as good in flow as the tallow amine naphthenate (made with straight chain fatty acids from beef tallow). These amine salts per se had no significant effect upon pour point, but only affected the flow rate."

EXAMPLE V PRIMARY AMINE SALTS In this example, a large series of amine salts representing the invention were added to the previously described Heating Oil, along with varying amounts of Pour Depressant A, and the resulting compositions were tested in Flow Tests B and A. The compositions tested and the results obtained are summarized in Table V which follows:

A series of hydroxy amine salts were prepared and tested as cold flow improvers in Heating Oil using Pour Depressant A and Flow Test B. The specific materials tested and the results obtained are summarized in the following Table V ll.

TABLE VlL-HYDROXY AMINE SALTS AS COLD FLOW Do Triac0ntan0ic 602 EXAMPLE VIII I-lydroxy Amine Salts Pumping Test Several blends were made of Heating Oil, with Pour Depressant A, and either triethanolamine stearate or tallow amine stearate (the tallow amine was made from hydrogenated tallow and comprised about 5 wt. palmityl amine, 35 wt. cetyl amine and 60 wt. stearyl amine). These blends were tested in a cold room as follows:

The cold room is lowered at 4 F. per hour from +35 to 40 F. The fuel blend (50 gallons) is contained in a typical 275-gallon tank connected through the usual fittings and a three-eighths inch copper line to a regular oil filter and oil burner pump in an adjoining room at about 60 to 70 F. The fuel blend is recycled from the tank through the filter and burner pump, and back to the tank until flow stops due to plugging. This test is useful in predicting the lowest temperature at which the fuel is operable as related to the coldest weather to be expected. It has been demonstrated that fuels which pass this test (pumping to -20 F. or lower) will perform well under actual winter field conditions where the temperature frequently drops as low as -30 F.

The composition tested and the test results are summarized in Table Vlll.

Table Vlll shows that the 0.05 wt. triethanolamine stearate was about as effective in improving the cold flow as 0.10 wt. of the Pour Depressant. Use of the combination of Pour Depressant and amine salt gave better results than either alone.

EXAMPLE IX Polyamine Salts A series of salts of equal molar equivalent ratios of polyamines and carboxylic acids were prepared (e.g. 1 mole of triethylene tetramine reacted with 4 moles of stearic acid) and tested in Heating Oil along with Pour Depressant A using Flow Test B. The specific salts tested and the results obtained are summarized in the following Table IX.

TABLE TX.POLYAMINE SALTS AS COLD FLOW IMPROVE RS Flow Amino salt Wt. Wt. percent test 13,

--- w we M01. percent a.i. pour dupercent Amino Acld wt. sult. prvsszmt A passage 'lrlvlhylvnvv Nunhtlmnlv. 1,046 0. [(1 0,02 83 lvtrnmlnv.

. (Hill 0. '2 101] lm Hti-urh- 1,28 1 0. U5 0. 02 100 While the preceding examples have demonstrated the invention with various pour point depressants, still other pour point depressants can be used, such as homopolymers of polyethylene having 3 to 12 methylene terminating branches per carbon atoms, polyethylene chlorinated with 5 to 35 wt. chlorine, etc. Also, for commercial application, concentrates in an inert carrier, such as a major amount of mineral oil, and about 1 to 20 wt. of the aforesaid nitrogen-containing material and about 2 to 29 wt. of the methylene backbone pour point depressant can be made for ease of shipping and handling. While substantially oil insoluble, the amides and salts of the invention, in a finely divided form, can be readily dispersed in the carrier by agitating thus making such concentrates practical.

What is claimed is 1. A fuel oil composition comprising middle distillate fuel containing n-paraffin wax, about .001 to 2 wt. of an oil-soluble polymethylene backbone pour point depressant having a molecular weight in the range of about 1,000 to 50,000 selected from the group consisting of:

a. copolymer of three to 40 molar proportions of ethylene per molar proportion of an ester of the formula:

R1 H (5:31 I l 3 3.

wherein R, is selected from the group consisting of hydrogen and methyl, R, is selected from the group consisting of OOCR and COOR., wherein R, is a C, to C alkyl group, and wherein R:, is selected from the group consisting of hydrogen and COOR b. copolymers of ethylene and vinyl chloride, and c. polyethylene chlorinated to contain about 5 to 30 wt.

chlorine, and about .001 to 1.0 wt. of a limited, solubility-in-oil nitrogen-containing material effective in modifying the crystal size of n-paraffin wax crystallizing from said distillate fuel, said material being selected from the group consisting of amides and salts of: A. an acid component selected from the group consisting 1. carboxylic acid of the general formula R(COO1-I),

wherein n is one to two and R is a C, to C hydrocarbon group which may be unsubstituted or hydroxy substituted,

2. phenol substituted with 0-3 alkyl groups of one to 12 carbons each,

3. inorganic acid, and

4. sulfonic acid of the formula RS0,0H where R is a C -C hydrocarbon group, reacted with:

B. a nitrogen component selected from the group consisting of: 1. ammonia, 2. monoamine of the formula:

/R2 R N wherein R, is a C, to C hydrocarbon group, and R and R are each selected 3. inorganic acid, and

4. sulfonic acid of the formula R-S0,0I-1 where R is a C -C hydrocarbon group, reacted with: B. a nitrogen component selected from the group consisting of:

l. ammonia,

2. monoamine of the formula:

wherein R, is a C to C, hydrocarbon group, R, and R are each selected from the group consisting of hydrogen and C to C hydrocarbon groups, said hydrocarbon groups being unsubstituted or hydroxy substituted and 3. ethylene polyamine having two to ten nitrogen atoms, said nitrogen-containing material having at least one straight chain hydrocarbon group of at least six carbon atoms and having a total number of carbon atoms in the range of about seven to 60, and wherein said methylene backbone pour point depressant has a number average molecular weight of about 1,000 to 5,000, and is a eopolymer of 3 to 40 moles of ethylene per molar proportion of an ester of the formula:

(i=3; 1 12 123 wherein R is hydrogen and R is selected from the group consisting of -OCR and -COOR wherein R is a C to C alkyl group, and wherein R is selected from the group consisting of hydrogen and COOR 2. A composition according to claim 1, wherein said material is an amide.

3. A composition according to claim 1, wherein said material is a salt.

4. A composition according to claim 1, wherein said acid component is a monocarboxylic acid and said nitrogen component is a primary monoamine.

5. A composition according to claim 4, wherein said acid is hydroxy substituted.

6. A composition according to claim 5, wherein said amine is an ethanol amine.

7. A composition according .to claim 1, wherein said material is an amide of a monocarboxylic acid and an ethanol amine.

8. A composition according to claim 1, wherein said material is a salt of monocarboxylic acid and ammonia.

9. A composition according to claim 1, wherein said material is the salt of a monocarboxylic acid and said monoamine.

10. A composition according to claim 1, wherein said material is a salt of a monocarboxylic acid and of an ethanol amine.

11. A composition according to claim 1, wherein said polymethylene backbone pour point depressant has a number average molecular weight in the range of about 1,000 to 5,000 and is a copolymer of 4 to 20 moles of ethylene and said ester, wherein said fuel is a heating oil, wherein the amount of said methylene backbone pour point depressant is in the range of 0.005 to 0.15 wt. and the amount of said nitrogen-containing material is in the range of 0.005 to 0.15 wt.

' l 2. A composition according to claim 11, wherein in said ester, R is hydrogen and R, is selected from the group consisting of OOCR and COOR, wherein R is a C to C alkyl group, and wherein R is selected from the group consisting of hydrogen and COOR 13. A composition according to claim 12, wherein said ester is vinyl acetate.

14. A composition according to claim 12, wherein said ester is isobutyl acrylate.

15. A composition according to claim 11, wherein said pour depressant is polyethylene chlorinated to contain about 5 to 35 wt. chlorine.

16. A fuel oil composition for heating comprising a major amount of fuel oil consisting essentially of middle distillate fuel and 0 to 70 wt. of residua fuel, 0.005 to 0.15 wt. of an oil-soluble polymethylene backbone pour depressant, having a molecular weight of about L000 to 5,000, which is a copolymer of 4 to 20 molar proportions of ethylene per molar proportion of an ester of the formula:

A. an acid component selected from the group consisting of:

l. carboxylic acid of the general formula R(COOl-I), wherein n is one to two and R is a C to C hydrocarbon group which can be unsubstituted or hydroxy substituted,

2. phenol substituted with one to three alkyl groups of one to 12 carbons each,

3. inorganic mineral acid, and

4. sulfonic acid of the formula R-SO OH where R is a C -C hydrocarbon group, reacted with:

B. a nitrogen component selected from the group consisting of: 1. ammonia, 2. monoamine of the formula:

/R2 R\-N\ wherein R is a C, to C hydrocarbon group, and R and R are each selected from the group consisting of hydrogen and C, to C hydrocarbon groups, said hydrocarbon groups being unsubstituted or hydroxy substituted,

3. ethylene polyamine having 2 to 10 nitrogen atoms,

said nitrogen-containing materials having at least one straight chain hydrocarbon group of at least six carbon atoms and having a total number of carbon atoms in the range of about 12 to 30.

17. An additive concentrate for treating fuel oil compositions containing distillate fuel oil to improve its cold flow properties comprising a major amount of a hydrocarbon carrier and about one to 20 wt. of finely divided limited, solubilityin-oil nitrogen-containing wax crystal modifier suspended in said oil, and about two to 29 wt. of a methylene backbone oil-soluble pour point depressant dissolved in said hydrocarbon carrier, said nitrogen-containing material being selected from the group consisting of amides and salts of:

A. an acid component selected from the group consisting of:

l. carboxylic acid of the general formula R(COOH),,

wherein n is one to two and R is a C to C hydrocarbon group which is unsubstituted or hydroxy substituted,

2. phenol substituted with zero-three alkyl groups of one to 12 carbons each,

from the group consisting of hydrogen and C 1 to C hydrocarbon groups, said hydrocarbon groups being unsubstituted or hydroxy substituted, and

3. alkylene polyamine having two to ten nitrogen atoms,

said nitrogen-containing material having at least one straight chain hydrocarbon group of at least six carbon atoms and having a total number of carbon atoms in the range of about seven to 60.

$ 22 8?" UNHED STATES PATENT @FFEQE @ERTHKQATE'QF QQRREQTEUN PatentNo. 3,658g a-93 Datei A riiagsg 1972 Inventor) William 0.. Hollyday Jr.

It is certified that error appears in the above-identified patent 7 and that said Letters Patent are hereby corrected as shown below:

Correct the title on the first page, and at the top I to read. of column 1 on the second page /"DISTILLATE FUEL OIL CONTAINING NITROGEN-CONTAINING SALTS OR AMIDES AS 'W'AX CRYSTAL MODIFIERS".

Column 12, lines 65 through column 13, line 2, cancel "3. inorganic acid, and we. each selected".

Column 13, line 5; cancel "ethylene" andsubstitute -'-a'lkyleneline 10 after "60" cancel the comma and substitute a period; lines 10 through 2l cance1 "and wherein said methylene backbone 9. of hydrogen and -COOR4."

Column 1 line 68 after -"to 60" cancel the period and add and mherein said methylene backbone pour point depres= sant has a number average molecular weight of about l,OOO"to 5,000 and is a copolymer of 3 to +0 moles of ethylene per molar proportion of an ester of the formula:

UNITED STATES WflENi @FFMIE QEMWQATE F QGRREQ'H.

Patent No. 39 5 9 93 Dated April 25 1972 Inventor(s) William co Hollyday, Jr

It is certified that error appears in the above-identified patent- A and that said Letters Patent are hereby corrected as shownvbelow:

a? Continued z as wherein R is hydrogen and R is selected from the group consisting of -OOCR and 00 34 wherein R is a C to C alkyl group and "wherein R is selected from the group consisting of hydrogen and -=OOR4.

Signed and sealed this 10th day of July 1973.

(SEAL) Attest:

EDWARD M.FLETCH'ER ,JR. Rene Teicmeysg-s AttestingOfficer Acting Commissioner of Patents 

2. A composition according to claim 1, wherein said material is an amide.
 2. monoamine of the formula: wherein R1 is a C1 to C21 hydrocarbon group, R2 and R3 are each selected from the group consisting of hydrogen and C1 to C8 hydrocarbon groups, said hydrocarbon groups being unsubstituted or hydroxy substituted and
 2. monoamine of the formula: wherein R1 is a C1 to C21 hydrocarbon group, and R2 and R3 are each selected
 2. phenol substituted with one to three alkyl groups of one to 12 carbons each,
 2. monoamine of the formula: wherein R1 is a C1 to C21 hydrocarbon group, and R2 and R3 are each selected from the group consisting of hydrogen and C1 to C8 hydrocarbon groups, said hydrocarbon groups being unsubstituted or hydroxy substituted,
 2. phenol substituted with zero-three alkyl groups of one to 12 carbons each, from the group consisting of hydrogen and C1 to C8 hydrocarbon groups, said hydrocarbon groups being unsubstituted or hydroxy substituted, and
 2. phenol substituted with 0-3 alkyl groups of one to 12 carbons each,
 3. inorganic acid, and
 3. alkylene polyamine having two to ten nitrogen atoms, said nitrogen-containing material having at least one straight chain hydrocarbon group of at least six carbon atoms and having a total number of carbon atoms in the range of about seven to
 60. 3. ethylene polyamine having 2 to 10 nitrogen atoms, said nitrogen-containing materials having at least one Straight chain hydrocarbon group of at least six carbon atoms and having a total number of carbon atoms in the range of about 12 to
 30. 3. inorganic mineral acid, and
 3. inorganic acid, and
 3. ethylene polyamine having two to ten nitrogen atoms, said nitrogen-containing material having at least one straight chain hydrocarbon group of at least six carbon atoms and having a total number of carbon atoms in the range of about seven to 60, and wherein said methylene backbone pour point depressant has a number average molecular weight of about 1,000 to 5,000, and is a copolymer of 3 to 40 moles of ethylene per molar proportion of an ester of the formula:
 3. A composition according to claim 1, wherein said material is a salt.
 4. A composition accorDing to claim 1, wherein said acid component is a monocarboxylic acid and said nitrogen component is a primary monoamine.
 4. sulfonic acid of the formula R-SO2OH where R is a C6-C36 hydrocarbon group, reacted with: B. a nitrogen component selected from the group consisting of:
 4. sulfonic acid of the formula R-SO2OH where R is a C6-C36 hydrocarbon group, reacted with: B. a nitrogen component selected from the group consisting of:
 4. sulfonic acid of the formula R-SO2OH where R is a C6-C36 hydrocarbon group, reacted with: B. a nitrogen component selected from the group consisting of:
 5. A composition according to claim 4, wherein said acid is hydroxy substituted.
 6. A composition according to claim 5, wherein said amine is an ethanol amine.
 7. A composition according to claim 1, wherein said material is an amide of a monocarboxylic acid and an ethanol amine.
 8. A composition according to claim 1, wherein said material is a salt of monocarboxylic acid and ammonia.
 9. A composition according to claim 1, wherein said material is the salt of a monocarboxylic acid and said monoamine.
 10. A composition according to claim 1, wherein said material is a salt of a monocarboxylic acid and of an ethanol amine.
 11. A composition according to claim 1, wherein said polymethylene backbone pour point depressant has a number average molecular weight in the range of about 1,000 to 5,000 and is a copolymer of 4 to 20 moles of ethylene and said ester, wherein said fuel is a heating oil, wherein the amount of said methylene backbone pour point depressant is in the range of 0.005 to 0.15 wt. %, and the amount of said nitrogen-containing material is in the range of 0.005 to 0.15 wt. %.
 12. A composition according to claim 11, wherein in said ester, R1 is hydrogen and R2 is selected from the group consisting of -OOCR4 and -COOR4 wherein R4 is a C1 to C4 alkyl group, and wherein R3 is selected from the group consisting of hydrogen and -COOR4.
 13. A composition according to claim 12, wherein said ester is vinyl acetate.
 14. A composition according to claim 12, wherein said ester is isobutyl acrylate.
 15. A composition according to claim 11, wherein said pour depressant is polyethylene chlorinated to contain about 5 to 35 wt. % chlorine.
 16. A fuel oil composition for heating comprising a major amount of fuel oil consisting essentially of middle distillate fuel and 0 to 70 wt. % of residua fuel, 0.005 to 0.15 wt. % of an oil-soluble polymethylene backbone pour depressant, having a molecular weight of about 1,000 to 5,000, which is a copolymer of 4 to 20 molar proportions of ethylene per molar proportion of an ester of the formula:
 17. An additive concentrate for treating fuel oil compositions containing distillate fuel oil to improve its cold flow properties comprising a major amount of a hydrocarbon carrier and about one to 20 wt. % of finely divided limited, solubility-in-oil nitrogen-containing wax crystal modifier suspended in said oil, and about two to 29 wt. % of a methylene backbone oil-soluble pour point depressant dissolved in said hydrocarbon carrier, said nitrogen-containing material being selected from the group consisting of amides and salts of: A. an acid component selected from the group consisting of: 